There was a new chicane at Monaco, the track having been extended out over the harbor to create a much slower kink than had previously been the case. The only change to the entry was that Patrick Tambay had a new Ford turbo engine in the back of his Beatrice Lola for the first time.

Qualifying resulted in pole position for Alain Prost (McLaren-TAG) with Nigel Mansell (Williams-Honda) and Ayrton Senna (Lotus-Renault) behind him. Then came Michele Alboreto's Ferrari and the improving Benetton-BMW of Gerhard Berger. The Brabham-BMW BT55 seemed to be getting better as well with Riccardo Patrese sixth ahead of Jacques Laffite's Ligier-Renault, Tambay, Keke Rosberg (McLaren-TAG) and Martin Brundle in the Tyrrell-Renault. The biggest surprise in qualifying was Johnny Dumfries's failure to qualify the second Lotus-Renault.

Laffite had to start from the back of the grid because he was not ready when the field set off for the final parade lap. The start was incident free and the top 10 then remained unchanged for the first few laps with Prost leading Senna, Mansell, Alboreto, a fast-starting Rosberg and Berger. The Austrian fell behind Patrese on lap 10 and on lap 16 Rosberg overtook Alboreto. He followed this up by overtaking Mansell on lap 26 and the Englishman then pitted for new tyres, which dropped him to fifth behind Alboreto. Patrese blew his chances by stalling during his pit stop. When the pits stops were over Prost led Rosberg and Senna. Mansell was fourth. Alboreto retired with a turbo failure and Berger went out with a hub problem. Further back there was a dramatic accident when Brundle and Tambay collided at Mirabeau, the Beatrice Lola somersaulting into the barriers. Both cars were out.

The order at the front did not change, however, and so Prost won from Rosberg with Senna third, Mansell fourth and the Ligiers of Arnoux and Laffite fifth and sixth.